521
FNCA52 TJSJ 080918
FWFSJU
FIRE WEATHER PLANNING FORECAST FOR PUERTO RICO
NATIONAL WEATHER SERVICE SAN JUAN PR
518 AM AST MON DEC 8 2025
DISCUSSION
SIMILAR WEATHER CONDITIONS ARE EXPECTED TODAY ACROSS THE CWA.
WINDS WILL REMAIN FROM THE EAST-SOUTHEAST BETWEEN 11 - 16 MPH,
WITH GUSTS UP TO 27 MPH. ADDITIONALLY, A DRIER AIR MASS CURRENTLY
FILTERING INTO THE REGION WILL TO A QUICK DROP IN RELATIVE
HUMIDITIES, WITH THE SOUTHERN COASTAL PLAINS AND HILLS OF PUERTO
RICO BELOW THRESHOLDS (BETWEEN 44 - 54 %). ALTHOUGH THESE
CONDITIONS MAY CONTRIBUTE TO THE SPREAD OF FIRE, A WIDESPREAD
THREAT IS NOT EXPECTED, AT MOST ELEVATED RISK OVER LOCALIZED
AREAS DURING PEAK HEATING. HENCE, THE FIRE DANGER THREAT WILL
REMAIN LOW TODAY, ANY UPDATES TO THE FORECAST WILL BE DONE IF
REQUIRED.
PRZ014-090930-
SOUTHEAST COASTAL PLAINS-
518 AM AST MON DEC 8 2025
TODAY TONIGHT TUE
CLOUD COVER MCLEAR MCLEAR PCLDY
PRECIP TYPE SHOWERS SHOWERS SHOWERS
CHANCE PRECIP (%) 10 20 30
TEMP (24H TREND) 86 (0) 69 (-3) 86
RH % (24H TREND) 44 (-18) 93 (+4) 54
WIND 20FT/EARLY(MPH) SE 16 G21 NE 9 SE 16 G21
WIND 20FT/LATE(MPH) SE 16 G21 NE 9 SE 16 G21
MIXING HGT(FT-AGL/MSL)4810 4030
TRANSPORT WND (MPH) E 16 E 15
VENT RATE (KT-FT) 67340 52390
DISPERSION 5 5
DSI 6 2 5
RH RECOVERY EXCELLENT
REMARKS...NONE.
PRZ015-090930-
SOUTHERN HILLS-
518 AM AST MON DEC 8 2025
TODAY TONIGHT TUE
CLOUD COVER MCLEAR MCLEAR PCLDY
PRECIP TYPE SHOWERS SHOWERS SHOWERS
CHANCE PRECIP (%) 20 10 30
TEMP (24H TREND) 84 (+3) 66 (-4) 84
RH % (24H TREND) 55 (-13) 99 (+5) 65
WIND 20FT/EARLY(MPH) SE 12 E 9 SE 12
WIND 20FT/LATE(MPH) SE 12 E 9 SE 12
MIXING HGT(FT-AGL/MSL)4890 4350
TRANSPORT WND (MPH) SE 15 E 14
VENT RATE (KT-FT) 63570 52200
DISPERSION 5 5
DSI 5 2 5
RH RECOVERY EXCELLENT
REMARKS...NONE.
PRZ016-090930-
NORTH COASTAL PLAINS-
518 AM AST MON DEC 8 2025
TODAY TONIGHT TUE
CLOUD COVER MCLEAR MCLEAR PCLDY
PRECIP TYPE SHOWERS SHOWERS SHOWERS
CHANCE PRECIP (%) 20 0 40
TEMP (24H TREND) 88 (+1) 67 (-4) 88
RH % (24H TREND) 51 (-13) 100 (+4) 59
WIND 20FT/EARLY(MPH) E 13 SE 9 E 12
WIND 20FT/LATE(MPH) E 13 SE 9 E 12
MIXING HGT(FT-AGL/MSL)4940 4480
TRANSPORT WND (MPH) E 13 E 10
VENT RATE (KT-FT) 54340 40320
DISPERSION 5 5
DSI 5 2 5
RH RECOVERY EXCELLENT
REMARKS...NONE.
PRZ017-090930-
NORTHERN HILLS-
518 AM AST MON DEC 8 2025
TODAY TONIGHT TUE
CLOUD COVER MCLEAR MCLEAR PCLDY
PRECIP TYPE SHOWERS NONE SHOWERS
CHANCE PRECIP (%) 10 0 50
TEMP (24H TREND) 86 (+1) 66 (-3) 86
RH % (24H TREND) 50 (-14) 100 (+4) 62
WIND 20FT/EARLY(MPH) E 11 SE 6 E 10
WIND 20FT/LATE(MPH) E 11 SE 6 E 10
MIXING HGT(FT-AGL/MSL)5250 4460
TRANSPORT WND (MPH) E 9 SE 9
VENT RATE (KT-FT) 42000 35680
DISPERSION 5 5
DSI 5 1 5
RH RECOVERY EXCELLENT
REMARKS...NONE.
PRZ018-090930-
WEST COAST-
518 AM AST MON DEC 8 2025
TODAY TONIGHT TUE
CLOUD COVER MCLEAR MCLEAR MCLEAR
PRECIP TYPE SHOWERS NONE SHOWERS
CHANCE PRECIP (%) 30 0 20
TEMP (24H TREND) 87 (0) 67 (-3) 87
RH % (24H TREND) 56 (-9) 99 (+5) 63
WIND 20FT/EARLY(MPH) E 16 E 9 SE 12
WIND 20FT/LATE(MPH) E 16 E 9 SE 12
MIXING HGT(FT-AGL/MSL)4790 3900
TRANSPORT WND (MPH) E 13 SE 8
VENT RATE (KT-FT) 52690 27300
DISPERSION 5 5
DSI 5 2 5
RH RECOVERY EXCELLENT
REMARKS...NONE.
PRZ019-090930-
EASTERN INTERIOR-
518 AM AST MON DEC 8 2025
TODAY TONIGHT TUE
CLOUD COVER MCLEAR MCLEAR PCLDY
PRECIP TYPE SHOWERS SHOWERS SHOWERS
CHANCE PRECIP (%) 20 20 20
TEMP (24H TREND) 85 (+2) 67 (-4) 85
RH % (24H TREND) 55 (-11) 100 (+4) 63
WIND 20FT/EARLY(MPH) SE 13 E 11 SE 12
WIND 20FT/LATE(MPH) SE 13 E 11 SE 12
MIXING HGT(FT-AGL/MSL)4600 4330
TRANSPORT WND (MPH) SE 16 SE 14
VENT RATE (KT-FT) 64400 51960
DISPERSION 5 5
DSI 5 2 5
RH RECOVERY EXCELLENT
REMARKS...NONE.
PRZ022-090930-
LUQUILLO MOUNTAIN RANGE-
518 AM AST MON DEC 8 2025
TODAY TONIGHT TUE
CLOUD COVER PCLDY PCLDY PCLDY
PRECIP TYPE SHOWERS SHOWERS SHOWERS
CHANCE PRECIP (%) 40 40 50
TEMP (24H TREND) 81 (+3) 66 (-3) 81
RH % (24H TREND) 61 (-12) 100 (+1) 69
WIND 20FT/EARLY(MPH) SE 12 E 9 SE 11
WIND 20FT/LATE(MPH) SE 12 E 9 SE 11
MIXING HGT(FT-AGL/MSL)4470 4300
TRANSPORT WND (MPH) SE 17 SE 15
VENT RATE (KT-FT) 67050 55900
DISPERSION 5 5
DSI 6 3 5
RH RECOVERY EXCELLENT
REMARKS...NONE.
PRZ023-090930-
CENTRAL MOUNTAIN RANGE-
518 AM AST MON DEC 8 2025
TODAY TONIGHT TUE
CLOUD COVER MCLEAR MCLEAR PCLDY
PRECIP TYPE SHOWERS NONE SHOWERS
CHANCE PRECIP (%) 30 0 50
TEMP (24H TREND) 84 (+4) 63 (-5) 84
RH % (24H TREND) 55 (-13) 100 (+5) 65
WIND 20FT/EARLY(MPH) SE 9 SE 5 SE 8
WIND 20FT/LATE(MPH) SE 9 SE 5 SE 8
MIXING HGT(FT-AGL/MSL)5510 4930
TRANSPORT WND (MPH) E 9 SE 9
VENT RATE (KT-FT) 44080 39440
DISPERSION 5 5
DSI 5 1 4
RH RECOVERY EXCELLENT
REMARKS...NONE.
PRZ024-090930-
CAYEY MOUNTAIN RANGE-
518 AM AST MON DEC 8 2025
TODAY TONIGHT TUE
CLOUD COVER MCLEAR PCLDY PCLDY
PRECIP TYPE SHOWERS SHOWERS SHOWERS
CHANCE PRECIP (%) 20 30 20
TEMP (24H TREND) 80 (+2) 66 (-3) 80
RH % (24H TREND) 61 (-11) 100 (+1) 70
WIND 20FT/EARLY(MPH) SE 11 E 6 SE 10
WIND 20FT/LATE(MPH) SE 11 E 6 SE 10
MIXING HGT(FT-AGL/MSL)4660 4110
TRANSPORT WND (MPH) SE 17 SE 15
VENT RATE (KT-FT) 69900 53430
DISPERSION 5 5
DSI 6 2 5
RH RECOVERY EXCELLENT
REMARKS...NONE.
PRZ025-090930-
VIEQUES-
518 AM AST MON DEC 8 2025
TODAY TONIGHT TUE
CLOUD COVER MCLEAR PCLDY PCLDY
PRECIP TYPE SHOWERS SHOWERS SHOWERS
CHANCE PRECIP (%) 20 50 60
TEMP (24H TREND) 86 (0) 73 (-1) 86
RH % (24H TREND) 55 (-7) 93 (+1) 59
WIND 20FT/EARLY(MPH) E 13 G17 E 12 SE 13 G17
WIND 20FT/LATE(MPH) E 13 G17 E 12 SE 13 G17
MIXING HGT(FT-AGL/MSL)4160 3690
TRANSPORT WND (MPH) SE 20 SE 15
VENT RATE (KT-FT) 70720 47970
DISPERSION 5 5
DSI 6 6 6
RH RECOVERY EXCELLENT
REMARKS...NONE.
PRZ026-090930-
CULEBRA-
518 AM AST MON DEC 8 2025
TODAY TONIGHT TUE
CLOUD COVER MCLEAR PCLDY PCLDY
PRECIP TYPE SHOWERS SHOWERS SHOWERS
CHANCE PRECIP (%) 20 50 60
TEMP (24H TREND) 87 (+1) 74 (-2) 87
RH % (24H TREND) 56 (-6) 94 (+2) 58
WIND 20FT/EARLY(MPH) SE 14 G18 E 12 SE 13 G17
WIND 20FT/LATE(MPH) SE 14 G18 E 12 SE 13 G17
MIXING HGT(FT-AGL/MSL)3820 3540
TRANSPORT WND (MPH) SE 21 SE 17
VENT RATE (KT-FT) 68760 53100
DISPERSION 5 5
DSI 6 6 6
RH RECOVERY EXCELLENT
REMARKS...NONE.
PRZ027-090930-
SOUTHWEST COASTAL PLAINS AND MONA ISLAND-
518 AM AST MON DEC 8 2025
TODAY TONIGHT TUE
CLOUD COVER MCLEAR MCLEAR MCLEAR
PRECIP TYPE SHOWERS SHOWERS SHOWERS
CHANCE PRECIP (%) 10 10 10
TEMP (24H TREND) 88 (+1) 69 (-4) 88
RH % (24H TREND) 43 (-19) 95 (+6) 55
WIND 20FT/EARLY(MPH) SE 20 G27 E 14 G17 E 17 G23
WIND 20FT/LATE(MPH) SE 20 G27 E 14 G17 E 17 G23
MIXING HGT(FT-AGL/MSL)4810 4270
TRANSPORT WND (MPH) E 20 E 15
VENT RATE (KT-FT) 81770 55510
DISPERSION 5 5
DSI 6 3 5
RH RECOVERY EXCELLENT
REMARKS...NONE.
VIZ001-090930-
SAINT THOMAS AND SAINT JOHN-
518 AM AST MON DEC 8 2025
TODAY TONIGHT TUE
CLOUD COVER MCLEAR PCLDY PCLDY
PRECIP TYPE SHOWERS SHOWERS SHOWERS
CHANCE PRECIP (%) 10 50 50
TEMP (24H TREND) 86 (+1) 72 (-4) 86
RH % (24H TREND) 58 (-7) 95 (+4) 61
WIND 20FT/EARLY(MPH) E 14 G18 E 12 SE 14 G18
WIND 20FT/LATE(MPH) E 14 G18 E 12 SE 14 G18
MIXING HGT(FT-AGL/MSL)3790 3600
TRANSPORT WND (MPH) SE 18 SE 18
VENT RATE (KT-FT) 60640 57600
DISPERSION 5 5
DSI 6 6 6
RH RECOVERY EXCELLENT
REMARKS...NONE.
VIZ002-090930-
ST CROIX-
518 AM AST MON DEC 8 2025
TODAY TONIGHT TUE
CLOUD COVER MCLEAR PCLDY MCLEAR
PRECIP TYPE SHOWERS SHOWERS SHOWERS
CHANCE PRECIP (%) 10 50 30
TEMP (24H TREND) 86 (+1) 73 (-2) 86
RH % (24H TREND) 60 (-4) 93 (+6) 60
WIND 20FT/EARLY(MPH) E 14 G18 E 12 SE 14 G18
WIND 20FT/LATE(MPH) E 14 G18 E 12 SE 14 G18
MIXING HGT(FT-AGL/MSL)4530 3990
TRANSPORT WND (MPH) E 21 E 18
VENT RATE (KT-FT) 81540 63840
DISPERSION 5 5
DSI 6 6 6
RH RECOVERY EXCELLENT
REMARKS...NONE.
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